class Message<T>{
    private T message;
    public T getMessage(){
        return message;
    }
    public void setMessage(T message){
        this.message=message;
    }
}
public class test2 {
    public static void main(String[] args) {
//        Message<String> message=new Message<>();
//        message.setMessage("你好");
//        fun(message);
        Message<Integer> message=new Message<>();
        message.setMessage(99);
        fun(message);
    }
    public static void fun(Message<?> message){
        System.out.println(message.getMessage());
    }
}
